Transportation is another sector that has increased its relative share of primary energy use. This sector has serious concerns as it is a significant source of CO2 emissions and other airborne pollutants, and it is almost totally based on oil as its energy source. An important aspect of future changes in transportation depends on what happens to the available oil resources, production and prices. At present, 95% of all energy for transportation comes from oil. (more…)

Indoor air quality (IAQ) research deals with the presence, levels, health effects, and control of physical, chemical, and biological factors in indoor environments, including homes, workplaces, and vehicles. IAQ research in industrialized countries has examined hundreds of specific factors (e.g., temperature, various chemicals, and mold), sources of pollution environment (e.g., environmental tobacco smoke, occupational factors, consumer cleaning products, and moisture), and control technologies (e.g., ventilation). (more…)

Taxation of energy in the United States, the federal government does not impose an energy tax or a general sales tax that is broadly applicable to energy. However, excise taxes are imposed on certain fuels, and there are a number of income tax provisions specific to the energy sector. There are three separate categories of taxes and fees that affect energy use: (1) excise taxes/fees that primarily affect energy demand; (2) income tax provisions that primarily affect energy supply by operating on the after-tax rate of return on investment; and (3) income tax provisions that primarily affect the demand for specific energy sources. (more…)

Federal Excise Taxes placed on specific energy sources tend to reduce energy demand for these energy sources in both the short and the long run. The federal government imposes excise taxes on almost all petroleum products (including petroleum additives) and coal (see Table 1). The federal government also imposes federal excise taxes on many transportation uses of methanol, ethanol, natural gas, and propane and imposes a fee on electricity produced from nuclear power plants and nuclear power electricity. (more…)

The term hybrid energy system refers to those applications in which multiple energy unit conversion devices are used together to supply an energy requirement. These systems are often used in isolated applications and normally include at least one renewable energy source in the configuration. Hybrid energy systems are used an alternative to more conventional systems, which typically are based on a single fossil fuel source. Hybrid energy systems may also be used as part of distributed generation application in conventional electricity grid. (more…)

In this new century, there is considerable pressure on the top six automakers to reduce their environmental and ecological footprint calculation. The automaker that wins the race to build and sell the superior car will shape consumer preferences, thereby boosting sales and profits. The winning firm will fashion a corporate strategy that drives automobile emissions to near zero while simultaneously providing high levels of performance, safety, and comfort. (more…)

Because transportation is such a large contributor to global warming, both globally and in the United States, climate and energy experts say finding clean alternatives to gasoline is also key to replacing fossil fuels and slowing global warming. Just as there is debate and competing research about which type of alternative transportation fuel should be developed to produce electricity, however, there is also competition among possible new transportation fuels. So far, in the United States, significant funding has been put into two transportation technologies—ethanol and hydrogen fuel cells. Many energy commentators say cars powered by electric batteries are the technology closest to mass production capability, however. (more…)

With ethanol’s future uncertain, many commentators see the transportation debate evolving into a war between two other technologies—hydrogen-powered fuel cells and battery powered electric vehicles. Some alternative fuel advocates are putting their support behind hydrogen, the most abundant element on Earth. Water, for example, is composed of hydrogen and oxygen molecules. Hydrogen can be produced from water by electrolysis, which separates the oxygen from the hydrogen. It can be used to power hydrogen fuel cells for vehicles (or to provide heat and electricity for buildings). Hydrogen fuel cells work by recombining hydrogen and oxygen—a process that produces electricity, heat, and water. Hydrogen-powered cars, therefore, could be an ideal transportation solution—nonpolluting, zero-emission vehicles that release only water, a natural and completely safe waste product. Also, fuel cells are highly efficient and powerful, and unlike typical batteries, fuel cells will never lose their charge as long as hydrogen fuel is supplied.

Hydrogen fuel cell technologies, however, must overcome many stubborn challenges before they can become a practical source of energy. Perhaps the biggest obstacle is cost; it currently takes more energy to make hydrogen than is produced, and production relies on expensive catalysts made from platinum, a scarce metal. And like biofuels, hydrogen is currently made using fossil fuels, so it is not emissions-free. In addition, liquid hydrogen fuel is highly flammable and must be stored at very low temperatures or under very high pressure, making transport and storage difficult. Switching vehicles to hydrogen fuel cell power also would require building a whole new infrastructure similar to the chain of gas stations that currently dot the landscape. Researchers are hoping to find answers to these problems by searching for other types of catalysts, studying other ways to improve production, and developing better hydrogen storage options.

Hydrogen researchers, however, have been promising breakthroughs since the 1990s with little progress to show for their efforts. Many observers are thus coming to the conclusion that the hydrogen fuel cell is a technology that will not be perfected in the near future. As physicist and climate expert Joe Romm explains, “Neither government policy nor business investment should be based on the assumption that these technologies will have a significant impact in the near or medium-term.” The Obama administration apparently agrees; it submitted a budget for 2010 that sharply cut back on government support for hydrogen projects. U.S. Energy Secretary Steven Chu explained the administration’s problems with hydrogen technology:

Right now, the way we get hydrogen primarily is from reforming [natural] gas. That’s not an ideal source of hydrogen. . . . The other problem is, if it’s for transportation, we don’t have a good storage mechanism yet. Compressed hydrogen is the best mechanism [but it requires] a large volume. We haven’t figured out how to store it with high density. What else? The fuel cells aren’t there yet, and the distribution infrastructure isn’t there yet. So . . . to get significant deployment, you need four significant technological breakthroughs. That makes it unlikely

Congress promptly reversed President Obama’s decision, however, restoring more than $200 million to 190 hydrogen projects around the country.

Smoke from biomass and coal combustion contains a large number of pollutants with known health hazards, including particulate matter, carbon monoxide, nitrogen dioxide, sulfur oxides (mainly from coal), formaldehyde, and polycyclic organic compounds (e.g., carcinogens such as benzo[a]pyrene). The concentrations of each of these pollutants vary among the different forms of solid fuels, with animal dung and crop residues having some of the highest level emissions to environment of particulate matter, one of the important indicator pollutants for health effects. (more…)

The product gas can be burned in boilers to generate heat and raise steam, in internal combustion engines to generate electricity and heat at small to medium scale (from a few kilowatts to a few megawatts), and in gas turbines to generate electricity (Brayton cycle) and heat at small to large scale. In large-scale systems using gas turbines, the exhaust gas from the gas turbine can be used to raise steam in a heat recovery steam generator to generate additional electricity using a steam turbine (Rankine cycle), resulting in combined cycle operation. (more…)